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1.
Aquat Toxicol ; 262: 106664, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37639824

RESUMO

Wildfires have emerged as a global ecological concern due to their wide-ranging off-site effects. One particular consequence is the adverse impact on aquatic environments, as wildfires are acknowledged as a significant source of aquatic contamination through ash runoffs containing toxic compounds. Yet, amphibian response to this source of contamination remains largely undocumented. This study assessed how ash runoffs from Eucalyptus sp. and Pinus sp. affect early aquatic life-stages of Xenopus laevis. Embryos and tadpoles were exposed, respectively, for 96 h and 14 days to serial concentrations (26.9% - 100%) of aqueous extracts of ashes (AEAs; 10 gL-1) composed of eucalypt (ELS) and pine (PLS) ashes. Mortality and development were monitored, and biometric data (snout-to-vent, tail and total length, and weight) measured. Sub-individual endpoints regarding oxidative stress (catalase-CAT; total glutathione-TG; lipid peroxidation-TBARS), neurotoxicity (acetylcholinesterase-AChE), transformation metabolism (glutathione-S-transferase-GST) and energetic metabolism (carbohydrate, lipid and protein content and O2 consumption), were also measured. The two AEAs induced no significant lethal effects on embryos or tadpoles. However, in general, AEAs caused a developmental delay in both life stages. Effects of AEAs on biometric endpoint were only reported for tadpoles, which showed a decreased body length (snout-to-vent, tail and total) and weight (embryos were not weighed), with PLS exerting higher effect than ELS. As for the sub-individual endpoints, embryos showed mostly no alterations on the activity of the monitored parameters, except for PLS, which reduced embryos' carbohydrate content (at ≥59.2%) and increased O2 consumption (at ≥35.0%). Regarding tadpoles, AEA exposure decreased the activity of CAT and GST (at ≥26.0%) and decreased carbohydrate (at ≥26.0%) and lipid (at ≥45.5%), whereas oxygen consumption increased (at ≥26.0%) only on PLS. Overall, the tested AEAs differentially affected amphibians across life-stages, indicating that plant coverage might affect ash toxicity.


Assuntos
Poluentes Químicos da Água , Incêndios Florestais , Animais , Xenopus laevis , Acetilcolinesterase , Poluentes Químicos da Água/toxicidade , Glutationa , Glutationa Transferase , Lipídeos
2.
Trop Anim Health Prod ; 55(4): 261, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37405611

RESUMO

This study evaluated the body condition score (BCS) at calving and breed (B) effects on milk composition, yield, performance, physiological parameters, hemogram, blood metabolites, and urinary metabolites in the transition and early lactation periods of Mediterranean (MED) and Murrah (MUR) buffaloes. Twenty MED and fifteen MUR buffaloes were distributed into four experimental treatments, in a completely randomized design, considering their racial groups and BCS (LBCS = low; HBCS = high): LBCS MED (N = 9); HBCS MED (N = 11); LBCS MUR (N = 8); HBCS MUR (N = 7). Animals were monitored during the last 21 days of gestation and first 56 days postpartum and kept under the same management and feeding conditions. During data collection, milk composition, yield, performance, physiological parameters, hemogram, blood metabolites, and urinary metabolites were evaluated. Higher milk production and fat-corrected milk were observed in MED than MUR buffaloes. Breed effects were observed on body weight, rectal temperature, glucose, urea, calcium (Ca) concentrations, and BCS effects on total protein, albumin, urea, and Ca. There were BCS effects on hematocrit, neutrophils, eosinophils, and interactions between B × BCS for lymphocytes and platelets. There were breed effects on urinary concentrations of chlorine, uric acid, and interactions between weight (W) × B on chlorine and urea. The MED buffaloes can be considered the most prepared to undergo physiological changes, including the BCS value at calving, indicating higher physiological health. Besides, this study demonstrates more considerable preparation for the calving, regardless of the body condition score at calving.


Assuntos
Bison , Búfalos , Feminino , Animais , Humanos , Cloro/metabolismo , Lactação/fisiologia , Leite/metabolismo , Período Pós-Parto/fisiologia , Grupos Raciais , Metaboloma
3.
Sci Total Environ ; 823: 153745, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35150685

RESUMO

The health effects of the particulate matter (PM) depend not only on its aerodynamic diameter (AD) and chemical composition, but also on the time activity pattern of the individuals and on their age. The main objective of this work was to assess the exposure of children to aerosol particles by using personal instruments, to study the particle size and composition of the inhaled PM, and to estimate their transport and deposition into the human respiratory tract (HRT). The average daily PM2.5 exposure was 19 µg/m3 and the size fractions with the greatest contribution to PM2.5 concentrations were 1 < AD <2.5 µm and AD <0.25 µm. Results indicated a contribution of 9% from the mineral aerosol, 7.2% from anthropogenic sulphate, 6.7% from black carbon and 5% from anthropogenic trace elements to the daily exposure to PM2.5. The levels of mineral and marine elements increased with increasing particle size, while anthropogenic elements were present in higher concentrations in the finest particles. Particle size has been shown to influence the variability of daily dose deposited between the extrathoracic and alveolar-interstitial zones. On average, 3% of the PM deposited in the bronchial region, whereas 5% to 8% were found in the bronchiolar region. The level of physical activity had a significant contribution to the total daily dose.


Assuntos
Poluentes Atmosféricos , Oligoelementos , Aerossóis , Poluentes Atmosféricos/análise , Criança , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Material Particulado/análise
4.
Sci Total Environ ; 806(Pt 1): 150491, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34844312

RESUMO

Polymethylmethacrylate (PMMA) production has increased almost 20% over the last years. With its release into the aquatic environment, its breakdown or degradation to nano dimensions (nanoplastics-NPLs) due to biological and physical/mechanical action is, theoretically, anticipated. The occurrence of PMMA-NPLs in aquatic ecosystems may thus cause adverse effects particularly to early life stages of amphibians, which may be in contact with PMMA-NPLs suspended in the water column or deposited in upper layers of the sediments. Accordingly, this work aimed at assessing the effects of PMMA-NPLs to aquatic early life stages of the model anuran species Xenopus laevis. To attain this objective, two types of toxicity assays were carried out by exposing embryos [Nieuwkoop and Faber (NF) stage 8-11] or tadpoles (NF 45) to three concentrations of PMMA-NPLs (1, 100 and 1000 µg/L): i) 96-h embryo teratogenicity assay, where survival, malformation, and total body length (BL) of embryos were assessed; and ii) 48-h feeding rate assay, where survival, feeding (FR), malformations and growth rates (body weight-BW and BL) of tadpoles were evaluated. PMMA-NPLs exposure had no significant effects on mortality, malformations of X. laevis embryos but BL was lower at 1000 µg PMMA-NPLs/L. In tadpoles, no effects on survival or FR were observed after exposure to PMMA-NPLs, but significant changes occured in BW and BL. Moreover, anatomical changes in the abdominal region (externalization of the gut) were observed in 62.5% of the tadpoles exposed to 1000 µg PMMA-NPLs/L. Despite the lack of knowledge regarding the environmental levels of NPLs, it is expected that sediments constitute a sink for these contaminants, where they can become available for organisms that, like tadpoles, feed on the organic matter at the surface of sediments. Considering the continuous release and subsequent accumulation of PMMA, the malformations obtained in the feeding assays suggest that, in the future, these nano-polymers may constitute a risk for aquatic life stages of amphibians.


Assuntos
Microplásticos , Polimetil Metacrilato , Animais , Ecossistema , Larva , Polimetil Metacrilato/toxicidade , Xenopus laevis
5.
Eur Ann Allergy Clin Immunol ; 54(4): 168-174, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33944542

RESUMO

Summary: Background. Acute urticaria is a common condition in the pediatric emergency department (ED) and no data is available in Portugal. Objective. We aimed to characterize the prevalence, etiology and management of acute urticaria in children presenting at an ED of a portuguese central hospital and report the follow-up investigation when drug or food allergy was suspected.Methods. Retrospective study of clinical records from children admitted to the ED with acute urticaria during one year period. Results. 250 children were included, mean age of 7.4 ± 4.9 years (0-17 years). The most frequently suspected etiological factors were infections (22%), foods (12%), insect bites (9%) and drugs (8%), of which, upper respiratory tract infections, seafood and ß-lactam antibiotics were the most frequent. In 44% of cases, the etiology of urticaria was not determined. After ED discharge, of the 50 patients with suggestive drug or food allergy, only 48% were sent to allergological workup and the allergy confirmed in 6 of them (2.4% of the 250 children). Conclusions. These data suggest that allergy is not the main trigger of acute urticaria in ED children, but when suspected, reference to an allergy department to complete allergological workup was insufficient.


Assuntos
Hipersensibilidade Alimentar , Urticária , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/epidemiologia , Hipersensibilidade Alimentar/terapia , Hospitais , Humanos , Encaminhamento e Consulta , Estudos Retrospectivos , Urticária/diagnóstico , Urticária/epidemiologia , Urticária/terapia
6.
J Hazard Mater ; 413: 125443, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33930964

RESUMO

The environmental effects of nanoplastics-NPLs have been addressed mainly through short-term exposures to a few types of polymers, neglecting other NPLs that are economically relevant like polymethylmethacrylate - PMMA. This work aimed to assess long-term effects of PMMA-NPLs on the marine primary consumer Brachionus plicatilis, evaluating the influence of different exposure routes (waterborne, foodborne and both) and food items (Nannochloropsis gaditana and Tetraselmis chuii). Rotifers were 21 days exposed to: a) control, with clean medium and food-CTR; b) contaminated medium (8.1 mg PMMA-NPLs/L) and clean algae-MC; c) clean medium and contaminated algae (pre-incubated for 96 h on 8.1 mg PMMA-NPLs/L)-AC; and, d) contaminated medium and algae-MC/AC. Mortality (lx), total number of organisms (TN), fecundity (mx), populational growth rate (r), generational time (gt), and feeding rates were assessed. Effects on r and mx were found after 21 days. Organisms from AC had higher r than MC. MC/AC organisms performed better than control in all endpoints. Overall organisms fed with N. gaditana had higher TN, mx and r than those fed with T. chuii. In the AC treatments, rotifers fed with N. gaditana had higher mx. Results highlight that exposure route and food type may modulate NPLs' effects, supporting the need for standardization of assays.


Assuntos
Clorófitas , Rotíferos , Poluentes Químicos da Água , Animais , Alimentos , Polimetil Metacrilato/toxicidade
8.
Biochem Biophys Rep ; 26: 100992, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33898765

RESUMO

This study aimed to assess the effect of supplementation with omega-3 in Wistar rats exposed to ionizing radiation in a dose of 18 Gy on the cortical electrical activity, using mathematical methods such as the power spectrum (PS) and the detrended fluctuation analysis (DFA) in the evaluation of the electrocorticogram (ECoG) record. The PS analysis showed that in non-irradiated animals but supplemented with omega-3 there was a decrease in the power of the beta rhythm, while the DFA applied to different frequency ranges of the ECoG showed a significant increase in the long-range correlation only for the theta wave when compared with non-supplemented animals. In the evaluation of the radiation effect through the PS, an increase in the power of the theta rhythm was observed in both groups (non-supplemented and supplemented animals) only when they were evaluated one week after irradiation. The DFA method also showed difference in this wave. The PS and DFA methods applied to the ECoG record allowed a quantitative analysis of the cortical electrical activity in rats in response to the omega-3 effects, ionizing radiation, or both.

9.
Chemosphere ; 264(Pt 1): 128403, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33007568

RESUMO

Natural populations are commonly exposed to sequential pulses of contaminants. Accordingly, this study aimed at testing the existence of an association between the tolerance to lethal levels of copper (Cu) and the survival recovery ability from pulsed partially lethal copper exposures in six clonal lineages of Daphnia longispina. It was hypothesized that the most tolerant genotypes would be the ones exhibiting a faster survival recovery from a pulsed contaminant exposure. For each clonal lineage, the intensity of pulses corresponded to the respective concentration of Cu causing 30% of mortality after 24h of exposure (LC30,24h). The initial hypothesis was not corroborated: obtained results showed no association between survival recovery and lethal tolerance to Cu. Nevertheless, some patterns could be detected. Firstly, the most sensitive lineages to lethal levels of copper revealed a faster survival recovery from a first Cu pulse comparatively to the most tolerant ones, though they were the most sensitive to a second pulse exposure. Secondly, the most tolerant lineages, though being more tolerant to a second exposure, exhibited the lowest survival recovery capacity after exposure to a first pulse of Cu. However, differences in the survival recovery capacity of the six clonal lineages after the exposure to the two pulses of Cu were not observed. Increasing the duration of the recovery period from 24h to 72h did not significantly alter mortality rates, except for the most sensitive and most tolerant clonal lineages. The results here obtained suggests that standard lethality assays may sub-estimate the toxicity of chemicals under realistic exposure scenarios, since sequential pulses are not infrequent in natural conditions.


Assuntos
Daphnia , Poluentes Químicos da Água , Animais , Bioensaio , Cobre/toxicidade , Genótipo , Poluentes Químicos da Água/toxicidade
11.
J Hazard Mater ; 402: 123773, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33254784

RESUMO

The current understanding of nanoplastics (NPLs) toxicity to freshwater biota, especially the potential toxic effects of polymethylmethacrylate (PMMA), remains limited. Thus, the present work intended to add knowledge about the ecotoxicity of ∼40 nm PMMA-NPLs focusing on lethality, morphology, feeding and regeneration capacity of the freshwater cnidarian Hydra viridissima, after an exposure period of 96 h. Results showed that high concentrations of PMMA-NPLs can impair the survival of H. viridissima, with an estimated 96 h-LC50 of 84.0 mg PMMA-NPLs/L. Several morphological alterations were detected at concentrations below 40 PMMA-NPLs mg/L, namely partial or total loss of tentacles, which, however, did not induce significant alterations on the feeding rates. Morphological alterations not previously reported in the literature were also found after the 96 h exposure, such as double or elbow-like tentacles. Exposure to 40 mg PMMA-NPLs/L significantly impacted hydra regeneration, with organisms exposed to PMMA-NPLs presenting significant slower regeneration rates comparatively to controls, but with no impacts on the feeding rates. Overall, this work highlights the need to assess the effects of NPLs in freshwater biota. Hydra viridissima species was sensitive in a wide range of endpoints showing its value as a biological model to study the effects of small plastic particles.


Assuntos
Cnidários , Hydra , Poluentes Químicos da Água , Animais , Água Doce , Microplásticos , Polimetil Metacrilato/toxicidade
14.
SEMERGEN, Soc. Esp. Med. Rural Gen. (Ed. Impr.) ; 46(4): 244-253, mayo-jun. 2020. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-197303

RESUMO

OBJETIVO: Describir el grado de actividad física (AF) de una muestra de ancianos independientes no institucionalizados y la relación entre aquel y el estado nutricional y las condiciones psicosociales de los ancianos. MATERIAL Y MÉTODOS: Estudio descriptivo transversal multicéntrico implementado en los centros de salud urbanos de la ciudad de Huesca en mayores de 75 años. Tamaño muestral 60 pacientes. Se analizaron variables demográficas, psicosociales, nutricionales, antropométricas y AF. Para la medición de esta última, se utilizó la escala breve de Minnesota en español (VREM). RESULTADOS: La edad media fue de 81,58 años (±4) con una distribución por género del 51,7% mujeres. El grupo mostró globalmente una situación de salud favorable: Afectación física leve (45%), correcta salud mental referida al estado cognitivo (93%) o de ánimo (88%), estado social favorable (96%), independencia para las actividades de la vida diaria (100%) y buena calidad de vida percibida (puntuación>70 en el 70%). En relación con la AF se obtuvo una media de 4666,2MET-min/14 días y se identificaron como sedentarios el 10% de los participantes. Se obtuvo una relación inversa estadísticamente significativa de la AF con la incapacidad funcional, la sarcopenia y la composición corporal (perímetro de cintura, diámetro abdominal sagital, índice de masa y porcentaje de grasa corporales) (p < 0,05). La AF no mostró relación significativa con el estado nutricional y las condiciones psicosociales. Sí resultó significativa la observada entre el estado nutricional y las variables de la esfera psicosocial (p < 0,01). CONCLUSIONES: Las características de la población estudiada en las esferas orgánica, funcional, psíquica y social no sugieren importantes limitaciones para la AF. Un porcentaje nada despreciable de ancianos no realiza suficiente AF. Existe una relación significativa entre la realización de ejercicio físico y los índices de composición corporal favorables


OBJECTIVE: To describe the level of physical activity (PA) of a sample of independent non-institutionalised elderly and its relationship between nutritional status and psychosocial conditions of the elderly. MATERIAL AND METHODS: A multicentre cross-sectional descriptive study carried out in Health Centres of the city of Huesca in a sample size of patients over 75 years-old. Demographic, psychosocial, nutritional, anthropometric, and PA variables were analysed. The short scale of Minnesota in Spanish (VREM) was used to measure the latter. RESULTS: The mean age was 81.58 years (±4) with a gender distribution of 51.7% women. The group were in a good health condition overall: Mild physical impairment (45%), correct mental health as regards cognition (93%) or mood (88%), favourable social status (96%), independence for activities of daily living (100%), and a good perceived quality of life (score>70 in 70%). There was a mean of 4666.2 METS-Min/14 days obtained in PA, and 10% of the participants were identified as sedentary. A statistically significant inverse relationship (P<.05) was observed between PA and functional disability, sarcopenia and body composition (waist circumference, sagittal abdominal diameter, mass index, and body fat percentage). No significant relationship was observed between PA and nutritional status and psychosocial conditions. The relationship between the nutritional status and the variables of the psychosocial sphere was significant (P<.01). CONCLUSIONS: The characteristics of the population studied in the organic, functional, psychical, and social spheres do not suggest important limitations for PA. An insignificant percentage of the elderly does not perform enough PA. There is a significant relationship between physical exercise and favourable body composition rates


Assuntos
Humanos , Masculino , Feminino , Idoso , Idoso de 80 Anos ou mais , Atividade Motora/fisiologia , Estado Nutricional/fisiologia , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Pesos e Medidas Corporais/estatística & dados numéricos , Desnutrição/epidemiologia , Condições Sociais/estatística & dados numéricos , Estudos Transversais , Psicometria/instrumentação , Nível de Saúde , Antropometria/métodos , Sarcopenia/epidemiologia , Estilo de Vida Saudável/classificação
15.
J Hazard Mater ; 394: 122522, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32200241

RESUMO

Mixed micelles of linear alkylbenzene sulfonic acid (LAS) and ether sulfate-based surfactants (SLEnS) can be added in household products and cleaning agents. SLEnS with higher ethylene oxide (EO) units in the head groups have economic and environmental advantages. This work aims to assess the influence of the number of EO units in the ecotoxicity of seven variants of SLEnS-LAS micelles (0-50 EO units) in soils. Ecotoxicological tests were carried out to assess emergence and growth of four plants species and reproduction of collembolans. Most of the variants inhibited plants growth at the highest concentrations (1237.5 µg SLEnS kg-1 of soildw). For reproduction, lower number of EO units resulted in EC50 from 924.2 (95 % CL: 760.7-1063.4) to 963.2 (95 % CL: 676.9-1249.6) µg SLEnS kg-1 of soildw, whereas for higher number of EO units (50 and 30) no inhibition was reported. Based on these results, we suggest that a higher number of EO units contribute to less hazardous formulations, confirming that different designs of surfactants may contribute to changes in the responses of terrestrial organisms. Therefore, we demonstrate that standardized ecotoxicological assays may contribute to more sustainable and effective formulations, when used upstream, prior to manufacture and marketing.


Assuntos
Artrópodes/efeitos dos fármacos , Micelas , Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Tensoativos/toxicidade , Animais , Benzenossulfonatos/química , Benzenossulfonatos/toxicidade , Etil-Éteres/química , Etil-Éteres/toxicidade , Estrutura Molecular , Reprodução/efeitos dos fármacos , Poluentes do Solo/química , Ésteres do Ácido Sulfúrico/química , Ésteres do Ácido Sulfúrico/toxicidade , Tensoativos/química
16.
Semergen ; 46(4): 244-253, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-31902675

RESUMO

OBJECTIVE: To describe the level of physical activity (PA) of a sample of independent non-institutionalised elderly and its relationship between nutritional status and psychosocial conditions of the elderly. MATERIAL AND METHODS: A multicentre cross-sectional descriptive study carried out in Health Centres of the city of Huesca in a sample size of patients over 75 years-old. Demographic, psychosocial, nutritional, anthropometric, and PA variables were analysed. The short scale of Minnesota in Spanish (VREM) was used to measure the latter. RESULTS: The mean age was 81.58 years (±4) with a gender distribution of 51.7% women. The group were in a good health condition overall: Mild physical impairment (45%), correct mental health as regards cognition (93%) or mood (88%), favourable social status (96%), independence for activities of daily living (100%), and a good perceived quality of life (score>70 in 70%). There was a mean of 4666.2 METS-Min/14 days obtained in PA, and 10% of the participants were identified as sedentary. A statistically significant inverse relationship (P<.05) was observed between PA and functional disability, sarcopenia and body composition (waist circumference, sagittal abdominal diameter, mass index, and body fat percentage). No significant relationship was observed between PA and nutritional status and psychosocial conditions. The relationship between the nutritional status and the variables of the psychosocial sphere was significant (P<.01). CONCLUSIONS: The characteristics of the population studied in the organic, functional, psychical, and social spheres do not suggest important limitations for PA. An insignificant percentage of the elderly does not perform enough PA. There is a significant relationship between physical exercise and favourable body composition rates.


Assuntos
Exercício Físico , Distância Psicológica , Qualidade de Vida , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Estado Nutricional
17.
Animal ; 14(2): 277-284, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31359853

RESUMO

The dietary inclusion of feed additives to improve the carcass characteristics of the final product is of great importance for the pork production chain. The aim of our study was to evaluate the effects of the association of ractopamine (RAC) and conjugated linoleic acid (CLA) on the performance traits of finishing pigs during the last 26 days prior to slaughter. In total, 810 commercial hybrid barrows were used. Animals were distributed among treatments according to a randomised block design in a 3 × 3 factorial arrangement, with three RAC levels (0, 5 or 10 ppm) and three CLA levels (0, 0.3 or 0.6%). Pigs fed the diet with 5 ppm RAC had higher average daily feed intake (ADFI) (2.83 kg; P < 0.05) when compared with those fed 10 ppm RAC and the control diet (2.75 and 2.74 kg, respectively). Lower ADFI values (P < 0.01) were observed with the diets containing CLA compared with the control diet with no CLA (2.73 and 2.75 v. 2.85 kg/day, respectively). The average daily weight gain of pigs fed 5 and 10 ppm RAC was +148 and +173 g/dayhigher (P < 0.001), respectively, than those fed the control diet. Dietary RAC levels influenced (P < 0.001) feed conversion ratio (FCR), which was reduced as RAC levels increased, with the pigs fed 10, 5 and 0 ppm RAC presenting FCR values of 2.57, 2.71 and 3.05, respectively. FCR also improved (P < 0.05) with the inclusion of 0.6% CLA relative to the control diet (2.70 v. 2.84, respectively). There was a significant interaction between CLA × RAC levels (P < 0.01) for final BW, loin eye area (LEA) (P < 0.05) and backfat thickness (BT) (P < 0.05). The treatments containing 10 ppm RAC + 0.6% or 0.3% CLA increased LEA and reduced BT. In conclusion, the level of 10 ppm inclusion of RAC increased the overall performance parameters of pigs and therefore improved production efficiency. The combined use of RAC and CLA promoted a lower feed conversion ratio as well as better quantitative carcass traits, as demonstrated by the higher LEA and lower BT. The dietary inclusion of CLA at 0.3% improved feed efficiency, however, without affecting LEA or BT yields.


Assuntos
Suplementos Nutricionais/análise , Ácidos Linoleicos Conjugados/farmacologia , Fenetilaminas/farmacologia , Carne Vermelha/normas , Suínos/fisiologia , Ração Animal/análise , Animais , Composição Corporal/efeitos dos fármacos , Dieta/veterinária , Masculino , Suínos/crescimento & desenvolvimento , Aumento de Peso/efeitos dos fármacos
18.
Sci Total Environ ; 698: 134155, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505347

RESUMO

Despite being considered environmentally safe, a deeper environmental risk assessment is needed for microbial insecticides; special attention should be devoted to their sublethal toxicity to non-target species. This study evaluated effects of VectoBac® 12AS - VB (based on the bacterium Bacillus thurigiensis var. israelensis) and Naturalis®-L - NL (based on the fungus Beauveria bassiana) on the aquatic insect Chironomus riparius life-history and biochemical responses. Acute tests estimated a 48 h-LC50 (median lethal concentration) of 1.85 µg/L (VB) and 34.7 mg/L (NL). Under sublethal exposure, VB decreased adults' emergence (LOEC - lowest observed effect concentration of 80 ng/L) while NL impaired larval growth (LOEC of 0.32 mg/L) and delayed emergence (LOEC of 2 mg/L for males and 0.8 mg/L for females). Despite not being monotonic, phenoloxidase activity increased (LOEC of 20 ng/L (VB) and 2 mg/L (NL)), suggesting activation of the immune system. There were no indications of oxidative damage nor neurotoxicity. Catalase activity was stimulated with all VB treatments, possibly associated with detoxification of immune response products. Under NL exposure, glutathione-S-transferase activity increased but did not show a dose-dependent response and, total glutathione decreased in the highest concentration. Exposure to both formulations caused the increase in protein content, while carbohydrate and lipids were not altered. This study revealed the susceptibility of C. riparius to VB and NL at concentrations below the ones recommended for field application, with potential population-level effects. These results add important information for the risk assessment of these microbial insecticides in aquatic ecosystems, considering relevant sublethal endpoints and raising concern about the adverse effects on non-target aquatic organisms.


Assuntos
Chironomidae/fisiologia , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bacillus thuringiensis , Beauveria , Feminino , Masculino
19.
Environ Pollut ; 258: 113805, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31883492

RESUMO

Ecological risk assessment associated with seawater intrusions has been supported on the determination of lethal/sublethal effects following standard protocols that force exposure neglecting the ability of mobile organisms to spatially avoid salinized environments. Thus, this work aimed at assessing active emigration from climate change-caused seawater intrusion into freshwater habitats. To specific objectives were delineated: first, to compute median 12-h avoidance conductivities (AC50,12h) for freshwater species, and second, to compare it with literature data (LC50,48 or 96h, EC50,6 or 21d) to assess the relevance of the inclusion of stressor-driven emigration into risk assessment frameworks. Four standard test species, representing a broad range of ecological niches - Daphnia magna, Heterocypris incongruens, Danio rerio and Xenopus laevis - were selected. The salt NaCl was used as a surrogate of natural seawater to create the saline gradient, which was established in a 7-compartment system. At each specific LC50, 48 or 96h, the proportion of avoiders were well above 50%, ranging from 71 to 94%. At each LC50, considering also avoiders, populations would decline by 85-97%. Furthermore, for D. magna and X. laevis it was noticed that at the lowest conductivities eliciting mortality, the avoidance already exceeded 50%. The results showed that the emigration from salinity-disturbed habitats exists and that can even be more sensitive than standard endpoints. Looking solely to standard endpoints involving forced exposure may greatly underestimate the risk of local population extinction, because habitat function can be severely disrupted, with subsequent stressor-driven emigration, before any adverse physiological effects at the organism level. Thus, the present study highlights the need to include non-forced exposure testing into ecological risk assessment, namely of salinity-menaced costal freshwaters.


Assuntos
Migração Animal , Mudança Climática , Ecossistema , Água do Mar/análise , Animais , Organismos Aquáticos , Água Doce
20.
Environ Pollut ; 257: 113547, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31733963

RESUMO

While commuting, individuals are exposed to high concentrations of urban air pollutants that can lead to adverse health effects. This study aims to assess commuters' exposure to particulate matter (PM) when travelling by car, bicycle, metro and bus in Lisbon. Mass concentrations of PM2.5 and PM10 were higher in the metro. On the other hand, the highest BC and PN0.01-1 average concentrations were found in car and bus mode, respectively. In cars, the outdoor concentrations and the type of ventilation appeared to affect the indoor concentrations. In fact, the use of ventilation led to a decrease of PM2.5 and PM10 concentrations and to an increase of BC concentrations. The highest inhaled doses were mostly observed in bicycle journeys, due to the longest travel periods combined with enhanced physical activity and, consequently, highest inhalation rates.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/análise , Material Particulado/análise , Automóveis , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Portugal , Respiração , Meios de Transporte , Ventilação
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